羰化法合成苯乙酸及其酯类的研究进展

综述了过渡金属催化的羰化法合成苯乙酸和苯乙酸酯近几十年来的研究进展。     

TiO~2光催化降解苯乙酸苄酯的研究

研究了苯乙酸苄酯在各种不同条件下的光化学反应和苯乙酸苄酯在TiO~2的悬浮体系中的光化学反应,比较了这两种条件下光降解的效果。并对反应机理进行了初步探讨。     

α-羰基苯乙酸酯合成方法的研究进展

综述了近30年α-羰基苯乙酸酯的重要合成方法,参考文献24篇。     

微波辐射活性炭负载磷钨酸催化合成苯乙酸β-苯乙酯

在微波辐射下,以活性炭负载磷钨酸(HPW／C)为催化剂,不用溶剂,合成了苯乙酸β-苯乙酯。优化反应条件为：负载量为23．6％的HPW／C 1g,苯乙酸30mmol,β-苯乙醇48mmol,微波辐射功率600W,辐射时间6min,产率87．3％。产物结构经IR表征。     

杀菌剂肟菌酯的合成工艺

以邻甲基苯乙酸为起始原料,经过氧化、酯化、肟化及溴代反应,最后与间三氟甲基苯乙酮肟缩合制备了杀菌剂肟菌酯.每步的反应产物均通过1 H NMR确认,总收率为17%.本工艺路线采用廉价的起始原料降低了生产成本,反应条件温和且易于控制,各步收率较高,有进一步研究与应用价值.     

吡啶-2-羧酸钴的CO加合性能与催化羰化合成苯乙酸研究

吡啶羧酸与过渡金属离子形成的配合物是一类重要的均相氧化、羰化、聚酮反应催化剂 ,这些催化剂对ＣＯ、Ｏ2 、ＲＣＨ =ＣＨ2 、ＲＸ、ＣＨ3ＯＨ等小分子均具有良好的活化功能 ,此类小分子均能在配合物分子中进行氧化加成插入、转位及还原消除等过程合成相应的有机化合物 ,其中吡啶 - 2 -羧酸钴对氧化羰化合成碳酸酯、聚酮显示出较好的催化活性[1,2 ] 。苯乙酸是医药、农药及香料合成的重要中间体 ,传统的合成路线为苯乙氰水解法。自本世纪 6 0年代以来 ,过渡金属配合物催化卤苄羰化合成苯乙酸的新方法引起了人们的极大兴趣。迄今 ,见诸文献…     

苯甲酸与苯乙酸的酸性强弱浅析

人们已经通过实验测得苯甲酸的离解常数为6.27×10~(-5),苯乙酸的离解常数为4.88×10~(-5),因此苯甲酸比苯乙酸的酸性强这是无疑的。然而在具体讨论其酸性强弱的原因时,现有的教材内容要么回避,要么涉及一点,未加阐述。作者在进修研究生的理论有机化学这门课时,自学了有关专著和文     

二正丁基锡对氨基苯乙酸酯配合物{[n-Bu2Sn(O2CCH2C6H4NH2-p)]2O}2的合成、结构及量子化学研究

二正丁基氧化锡和对氨基苯乙酸按1:1反应,合成了二正丁基锡对氨基苯乙酸酯配合物{[n-Bu2Sn(O2CCH2C6H4NH2-p)]2O}2.经X-射线衍射方法测定了其晶体结构,结构属单斜晶系,空间群P21/n.配合物是以Sn2O2构成的平面四元环为中心环的二聚体结构,锡原子均为五配位的畸变三角双锥构型.对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及一些前沿分子轨道的组成特征.     

新型吸附树脂对苯乙酸的吸附热力学研究

研究了苯乙酸在新型超高交联树脂AH、NDa-150和大孔吸附树脂(Amberlite XAD-4)上的平衡吸附数据，测定了288K、303K和318K温度下的吸附等温线，结果表明吸附过程符合Langmuir吸附等温方程。苯乙酸在AH、NDa-150上的吸附容量分别比在Amberlite XAD-4上的吸附容量最高高出90％、113％，这主要归因于AH、NDa-150表面的极性基团及树脂的微孔结构．Langmuir吸附等温线、相对吸附容量以及等量吸附焓变表明，苯乙酸在AH树脂上的吸附是物理吸附和化学吸附共同作用的结果．对苯乙酸被3种树脂吸附的吸附焓变、自由能变、吸附熵变也作了计算，并对吸附行为作了合理的解释。     

稀土固体超强酸SO2-4/TiO2/La3+催化合成苯乙酸乙酯

苯乙酸乙酯,常作为修饰剂和主香剂,应用于烟草、食品、日用化妆品等行业,还可以用于生产巴比妥类催眠药鲁米那,也可作溶剂.工业生产中采用硫酸催化合成苯乙酸乙酯,但硫酸有脱水和氧化作用,生成众多副产物,产物后处理工艺复杂,污水排放量大,严重腐蚀设备.本文合成了稀土固体超强酸SO2-4/TiO2/La3+催化剂,考察了影响催化活性的一些因数及催化合成苯乙酸乙酯的条件.此催化剂不仅克服了浓硫酸催化的一些缺点,而且酯化率高,反应时间缩短一半,反应温度降低15℃,容易回收、可以多次重复使用,适宜工业生产.     

Reductive photoalkylation of flavin nuclei and flavin-catalyzed photodecarboxylation of phenylacetate

Structure and properties of leucoflavin derivatives obtained through flavinsensitized photodecarboxylation of phenylacetate ions are described. The photoreduction of flavin with phenylacetate as donor is shown to be a quantitative photoalkylation, the benzyl residue entering either position 5 (nitrogen) or the bridge position 4a (carbon) of the flavin nucleus, depending on the conditions. The isomers were isolated, and identified by IR., NMR., and elementary analysis. The benzyl residue migrates from N(5) to C(4a) upon heating.     

Electric dipolemoment of amyl cinnamate, amyl phenylacetate, phenyl propyl butyrate, geranyl formate and glyceryl triacetate

Electric dipolemoments of amylcinnamate, amyl phenylacetate, phenyl propylbutyrate, geranyl formate and glyceryl triacetate have been determined in benzene solution at a frequency of 1 Mc/s. The observed values of dipolemoments indicate the existence a cis- configuration in geranyl formate and a trans- configuration in amyl cinnamate, amyl phenylacetate and phenyl propylbutyrate, in which the C---O---C plane lies considerably out of the trans- plane.     

New approach to 4-phenyl-β-aminotetralin from 4-(3-halophenyl)tetralen-2-ol phenylacetate

Mixed trifluoroacetyl phenylacetyl anhydride and 3-halostyrenes (fluoro, chloro, and bromo) or vinylcycloalkanes (cyclohexyl and cyclooctyl), undergo cascade Friedel-Crafts cycli-acylalkylation, enolization, and O-acylation to give 4-substituted tetralen-2-ol phenylacetates, without additional solvent in good yields. Base alcoholysis of 4-phenyltetralen-2-ol phenylacetate reveals the tetral-2-one for asymmetric transfer hydrogenation. Bromophenyltetralen-2-ol phenylacetate undergoes Suzuki coupling, and provides a short route to trans-4-phenyl-β-aminotetralin.     

Synthesis and spectroscopic studies of some heterocyclic compounds. Reaction of 3-aryl-1-phenyl-2-propen-1-ones with ethyl phenylacetate

3-Aryl-1-phenyl-2-propen-1-one I reacted with ethyl phenylacetate (II) in the presence sodium ethoxide at room temperature to give the corresponding ethyl β-aryl-γ-benzoyl-α-phenyl-butyrate III. However,' when the same ketones were refluxed with ethyl phenylacetate, they gave the corresponding 4-aryI-3,6-diphenyl-3,4-dihydro-2H-pyran-2-ones IV. The reactions of III and IV with hydrazine hydrate afforded the corresponding hydrazones VI and 2-pyridones VIII, respectively. The structure and configuration of the products are based on chemical and spectroscopic evidence.     

Conversion of phenylacetonitrile in supercritical alcohols within a system containing small volume of water

The reaction of phenylacetonitrile in supercritical methanol and ethanol in a system containing a small volume of water was studied. The effects of various operating conditions, such as reaction temperature, reaction time, the mole ratio of phenylacetonitrile/water/methanol or ethanol on the product yield were systematically investigated. The optimal yield of methyl phenylacetate for phenylacetonitrile in supercritical methanol in a system containing a small volume of water was 70 % at 583 K and 2.5 h. The optimal yield of ethyl phenylacetate for phenylacetonitrile in supercritical ethanol with a small volume of water was 80 % at 583 K and 1.0 h. At the same time, a feasible mechanism was proposed for phenylacetonitrile in supercritical methanol and ethanol in a system containing a small volume of water.     

Comparisons of Photo‐Fries Rearrangements of 4‐Dodecylphenyl Phenylacetate and Two Structurally Related Esters in Hexane and Polyethylene Cages. How Important Are Anchoring Chains?†

Photo-Fries rearrangements of 4-dodecylphenyl phenylacetate have been investigated in polyethylene films with 0-71% crystallinity and in hexane over a range of temperatures. The results are compared to those reported previously from phenyl phenylacetate and 1-naphthyl tetradecanoate to assess the influence of a long alkyl chain on the in-cage motions of the intermediate singlet radical pairs. It is demonstrated that the reactivity and selectivity of intimate singlet radical pairs can be tuned by judicious placement of long-chain substituents and selection of a specific polyethylene type as the reaction matrix.     

Effect of phenyl substituent on the dimerization of copper(II)-carboxylate in solvent extraction of copper(II) with phenylacetic acid

The effects of the phenyl substituent on the dimerization of copper(II) carboxylate in the solvent extraction of copper(II) with phenylacetic acid using benzene and 1-octanol as a solvent were investigated, at 25 degrees and at the aqueous ionic strength of 0.1M (NaClO(4)). The dimerization of copper(II) phenylacetate has been found to be written as: 2CuA(2)Cu(2)A(4) in 1-octanol, and 2CuA(2)(HA)(2)Cu(2)A(4)(HA)(2) + (HA)(2) in benzene, with the dimerization constants, log K = 2.24 and log K = 4.19, respectively. It was proved that the phenyl group inhibits the formation of the dimeric copper(II) phenylacetate, and its effect is partially shielded by a methylene substituent.     

西柏三烯-4,6-二醇衍生物的合成及抗肿瘤活性

以烟草中含量丰富的大环二萜类化合物2,7,11-西柏三烯-4,6-二醇(CBT)为母体, 其C6位羟基经酯化/醚化, 合成了28个西柏三烯-4-醇-6-羧酸酯及西柏三烯-4-醇-6-烷氧类化合物. 采用核磁共振波谱(NMR)和高分辨质谱(HRMS)对目标化合物进行了结构表征, 并初步评价了其生物活性. 细胞毒活性测试结果表明, 部分化合物对肿瘤细胞的抑制作用与阳性对照顺铂相当, 其中α-2,7,11-西柏三烯-4-醇-6-O-苯乙酸酯(1i)对乳腺癌细胞株MCF-7的IC₅₀值为15.45 μmol/L, α-2,7,11-西柏三烯-4-醇-6-O-(2-氟)苯乙酸酯(1t)对肺癌细胞株SMMC-7721的IC₅₀值为11.44 μmol/L.     

Heterogeneous acylation of phenol with acetic anhydride over hydrotalcite-like compounds

Liquid phase acylation of phenol with acetic anhydride was studied over the mixed oxides obtained from Mg-Al, Ni-Al, and Cu-Al hydrotalcites (HTs). The mixed oxides were characterized by XRD and SEM. The main acylation products of phenol over these oxide catalysts are phenylacetate and o-hydroxyacetophenone.